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alexgartrell

2,937 karma · joined March 25, 2009

SWE @ Thinking Machines Previously Operating Systems, etc @ Meta

Computers are cool

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alexgartrell··on In Defense of the Best
Nothing lasts forever, and as far as industries go, Tobacco has done very, very well.
alexgartrell··on Ask HN: Is Google still a cool place to work?
A little under two years ago I got offers from both Facebook and Google. The Google offer was a lot bigger (including in stock, the break even point was a valuation of 50 bln), but I accepted the Facebook offer instead, because I knew I'd only get to work on the kind of infrastructure projects I wanted to work on at Facebook. Bootcamp beats the hell out of preallocation for things like this.
alexgartrell··on T.js - A tiny templating framework in ~400 bytes

  render("{a} is all that I've {a}", {'a' : 'b'});
  "b is all that I've b"
  render("{a} is all that I've {{a}}", {'a' : 'b'});
  SyntaxError: Unexpected token {
Seems Legit
alexgartrell··on Is Nginx obsolete now that we have Amazon CloudFront?
> How does this shit make it to the front page?

Obviously the title was a little ridiculous, but I up-voted it, because it's a novel idea. If you're planning to have almost all of your static assets hosted from the CDN (which is pretty reasonable for almost everyone) then why bother with a super high-throughput low-latency web server if the only purpose is to occasionally refill the CDN? If you end up thrashing the CDN and constantly going back to refill it, you're going to have bigger problems.

From what I can tell, the rest of your comment is just super aggressive and doesn't really go anywhere. I will tell you that I have extensive experience with every piece you've mentioned here, and none of that really has any effect on the author's thesis (again, no need to optimize serving static content from your host if a CDN is going to do the legwork).

In general though, when someone works at Mozilla, I tend to give them the benefit of the doubt regarding their knowledge of elementary computing principles.

alexgartrell··on My thoughts on MessagePack
> They could store more objects in a server without performance declination (e.g. gzip).

The performance declination argument is bullshit. Network's a million [0] times slower than gzip.

Truth be told, once you're on the network, you're already screwed w.r.t. most serialization. The only thing efficient compression/decompression is going to buy you is lower CPU (memcached servers run at like 2% CPU util, even under heavy load [1]).

Memcache at Facebook actually uses the ascii protocol, and the memcached implementation is a braindead strtok parser (some of our other stuff uses ragel -- you'll have a hell of a time out optimizing ragel with the right compiler flags -- I've tried and failed).

Just use whichever serialization format has the best API, because I can say with near certainty that it's not going to be a perf problem for you if you're touching disk, network, etc.

[0] Obviously a made up number, but it's way slower. Especially if you're unlucky and lose a packet or something.

[1] With the exception of weird kernel spin lock contention issues, which can happen if you're not sharding your UDP packets well and trying to reply from 8+ cores on 1 UDP socket. You probably aren't.

alexgartrell··on Encrypted Chat Developer Detained, Interrogated at US Border
The introduction of rape as a metaphor serves an emotional purpose, not a logical one.

Working on encryption software : Being questioned at the border !:: Wearing a bikini : getting raped.

It's a lazy argument and he was right to point it out.

alexgartrell··on Reticent rich: Preferred style in Silicon Valley
The "zuckerberg's underlings" thing was a load of bullshit. I've seen a corvette, an r8, a lotus, and various other really nice cars at work. You can drive whatever you want, just don't be an asshole about it.
alexgartrell··on Here's Why Google and Facebook Might Completely Disappear in the Next 5 Years
"What's black and white and re[a]d all over? Nothing anymore"
alexgartrell··on Lessons from Sheryl Sandberg: Stop Working More Than 40 Hours a Week
I work at Facebook, do not work very many hours (9:30-5:30 most days, including breakfast, lunch and sometimes an hour-long workout at the gym), and have never heard so much as a suggestion that I work more. This was also true during lockdown. The truth is, if you are capable of getting a lot of shit done, people are just happy that you're able to give them a lot, they don't squeeze every productive second out of you.

I attribute the 24/7 lockdown stuff to people who wear it as a badge of honor (that's exactly how Carnegie Mellon was, at least).

alexgartrell··on Coding is priority number five
who?
alexgartrell··on A behind-the-scenes look at Facebook release engineering
It's been a while since I've had to deal with it (bootcamp), but I'm pretty sure we still use Watir [1]

[1] http://watir.com/

alexgartrell··on A behind-the-scenes look at Facebook release engineering
As I understand it, the main reason is that IRC is decoupled from Facebook completely (or should be). In "Oh shit, the sky is falling!" SEV situation we can trust (sorta) that IRC will be there.
alexgartrell··on 7 Years Of YouTube Scalability Lessons In 30 Minutes
As a datapoint, we use jitter a lot in cache infrastructure at Facebook
alexgartrell··on Paul Graham has lost the plot
The thing about proof by contradiction is that you can invalidate it by showing that the contradiction is not, in fact, a contradiction.

Linux is used everywhere, but it's also paid for. If it weren't paid for, it wouldn't be used everywhere.

alexgartrell··on Paul Graham has lost the plot
Linux is subsidized by large players who need an open platform on which to provide other services. This includes companies like Google who provide advertising based upon things that run on linux and companies like IBM who sell proprietary software that runs on Linux and support contracts for those products.

There are very few viable, large-scale open source projects that are run on developer free time alone.

alexgartrell··on Why Systems Programmers Still Use C (2006)
I've read many of your comments on this thread, and I believe most of them to be unrealizable for non-trivial applications. Anyone can write a simple web-service, but how does one write a super low latency network file system in such a way that "security is obvious?"
alexgartrell··on Building data structures that are smaller than an array and faster (in C)
I agree with your point 100%, but if they're sorted you could probably just store the deltas an then use something like the varints that google protocol buffers to compress those deltas down from 32 bits (with a thousand of them, you are guaranteed that some of the deltas will be less than 22 bits because 1000 * 2^22 > 2^32).

With custom compression, where there's a will there's generally a way :)

alexgartrell··on Mozilla partners up with LG to combat Apple and Google with its own device
I don't work for Mozilla, don't use Firefox, and am not a front-end developer (I write C). That said, I agree 100% that Apps of the future will be delivered over HTTP to general purpose runtimes that will essentially be browsers (maybe they'll drop the need to wrap everything in chrome, or something).

Browsers are increasingly become a dynamic language runtime attached to a powerful graphics rendering library. Make the runtime faster, provide better graphics widgets, and get past this "remote everything with shitty local caching" thing and you've got yourself one hell of a toolkit.

alexgartrell··on Facebook Shakes Hardware World With Own Storage Gear
I think this is a little unfair. Lots of people skim the comments before going to the article, and they'd assume you meant that there's no content there (other than "Facebook will talk about it in May"), but they actually did talk to a source or two at Facebook and they actually do mention Rackspace's open virtualization stuff.

I thought it was a cool article.

alexgartrell··on Google to Sell Heads-Up Display Glasses by Year’s End
I would never claim that sarcasm is always unwanted, but it's probably used an order of magnitude or two more frequently than is useful.

The problem is part of a larger one, people seem to be generally more interested in pithy, memorable one liners than in starting a discussion -- the easiest way to do this is to say something vitriolically sarcastic. People who agree with you will up-vote you, and you'll get some measure of affirmation from that.

The issue with that approach is that Hacker News should be a place where discussion flourishes. If the parent had said something to the effect of "This presents a troublesome, albeit interesting, avenue for further data aggregation, which could be used to target ads or sold to third parties," it would have likely kicked off an interesting discussion (both about the feasibility of such data aggregation (computer vision, mobile aggregation, etc.) and the societal costs of allowing such aggregation).

Instead, he went for the funny one-hitter, which framed the debate in such a way (by suggesting that it was inevitable and going to be used for evil) that anyone with even a slightly differing opinion is prevented from saying anything.

I don't mean to single out mechanical_fish specifically, many people here are guilty of this, but it essentially makes Hacker News more of an announcement/sharing forum (like twitter) than a discussion forum, which was one of the things that attracted me (and I'm sure many others) to it in the first place.

So I guess my larger point is that we should be more mindful of this stuff. It's more important to frame a relevant discussion than it is to "be right," and we should embrace that by posing interesting questions and answering them deliberately (being careful to stick to facts and being careful with the speculation, which easily morphs into FUD).

alexgartrell··on Google to Sell Heads-Up Display Glasses by Year’s End
Man, you've been around here for two years longer than I have. You know that there's no value added by blatant sarcasm. If you're actually afraid that Google will use your captured images to serve you unwanted ads (and, btw, revolutionize computer vision in the process), then say exactly that. Crackin' wise about snackwells isn't getting anyone anywhere.
alexgartrell··on How key-based cache expiration works
I work on memcache at Facebook, and cache invalidation is a hard, hard problem. It's easy to think that we just overlooked this trivial fix, but the reality is that this just doesn't solve all possible cache consistency problems. Namely, how do you deal with racing writes where the clocks are skewed? How do you deal with multiple copies of the same data in different caches (different data centers, for example). What about axe-murdering your top level db because that data is inherently uncacheable using this scheme?

I'm not trying to hate on the post at all, I think it's awesome that product people are thinking about this problem, and the more of them that do the better the world is going to be for guys like me. I just want them to continue to think hard about it :)

alexgartrell··on What I learned interviewing with Google
I'm not saying it's a perfect indicator, I'm saying it's a cheap and easy indicator. Certainly there are outliers in every direction, but a running back who runs a 5.0 forty just isn't going to be very good (unless he's like 400 pounds).

So is it more likely that Google is filled with idiots that can't see the err of their ways, or that, across tens of thousands of individual hires, this is the most cost effective and produces the best results (minimizing false positives) on average.

College-admissions style interviewing just doesn't make sense for a company like Google.

FWIW, there are a couple edge cases (like javascript/frontend engineers) which my company (Facebook) has completely separate hiring tracks for. It works for us, but I'm sure Google has its own reasons for not doing that.

alexgartrell··on What I learned interviewing with Google
The forty yard dash provides one of the most important signals for football recruiting. Essentially, it's a measurement of the time from when the athlete takes his hands off of the start line to when he crosses the finish line. Most commonly, it is run in cleats on grass with no pads, and certainly no players trying to prevent you from reaching the goal line. In addition to that, the best technique for running a forty, literally falling forward to build momentum before lifting your hand off the ground, is actually illegal for offensive players (and pretty pointless for defensive ones).

So why is this completely unrelated activity so important for measuring football players? Because it takes ten seconds to measure, and a guy who can run a 4.2 forty can almost always play pretty damn well.

Tech interviews today are a low cost way of getting a rough idea of ability to code. Judging from Google's output, it's pretty damn effective for them.

alexgartrell··on Google Near Launch of Cloud-Storage Service
http://en.m.wikipedia.org/wiki/Google_File_System

If amazon can build it, Google can build it.

alexgartrell··on GUM: A better CLI for Git
git reflog is the SINGLE most undersold feature of get. It's a global, perpetual undo function (less garbage collection, which I understand to be discouraged).
alexgartrell··on Google is FUBAR
> As far as SPYW goes, it's all about giving the users more relevant results.

For the majority of users, Facebook/Twitter results are more relevant than Google Plus results. There's nothing in the rule book that says you can't leverage a successful property to promote another, but it's unfair to everyone to try to pass that off as a move to increase relevance in search results.

Disclaimer: I'm a Facebook engineer who doesn't take SPYW personally.

alexgartrell··on Why Tarsnap won't use DynamoDB
This is an awesome idea. Do this.
alexgartrell··on Google Fires Back at Twitter: You Took Yourself Out of Search
You already disclose your employer in your profile, but you're probably going to want to do it in posts as well.

As a counterpoint though, I would argue that Google Chrome using Google services (seemingly exclusively) for its sync functionality kind of looks like a business decision more so than experimentation with poorly defined standards.

alexgartrell··on Nginx 0mq transport layer for communicating with upstream servers
I was one of the first committers on Mongrel2 (actually, second behind Zed) and I still am (though mostly as a historical accident, I haven't contributed anything of substance since SSL).

In my opinion, this is great. I think Mongrel2 is an excellent proof-of-concept, and if it provided the impetus for a much more widely used project like nginx to go down a similar path (though it's just a module right now), then everyone wins.

That said, this certainly isn't in nginx mainline, and it's very feature poor as compared to Mongrel2. One could not simply swap in nginx with this module for an existing Mongrel2 installation.

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